for($i=0;$i<count($users)+1;$i++){
    for($j=$i+1;$j<count($users);$j++){
        if($users[$i]['name'] == $users[$j]['name']){
            for($k=0;$k<count($users[$i]['ip']);$k++){
                for($l=0;$l<count($users[$j]['ip']);$l++){
                    if($users[$i]['ip'][$k] == $users[$j]['ip'][$l]){
                        unset($users[$j]['ip'][$l]);
                        $users[$j]['ip'] = array_values($users[$j]['ip']);
                    }
                }
            }
            for($l=0;$l<count($users[$j]['ip']);$l++)
                $users[$i]['ip'][] = $users[$j]['ip'][$l];
            $users[$i]['ip'] = array_unique($users[$i]['ip']);
            unset($users[$j]);
            $i--;
            $users = array_values($users);
        }
    }
}
print_r($users);